The organic light emitting diode (OLED) is a light emitting diode including a light emitting layer composed of an organic compound. The OLED has a light weight, thin thickness, multi-color, and low manufacturing cost. Thus, the OLED has been widely used in various fields.
The carbon nanotube composite structure formed by carbon nanotubes and polymer can be used as the electron transport layer of the OLED. The carbon nanotube composite structure can be formed by two methods. One method includes dispersing the carbon nanotubes into an organic solvent to form a carbon nanotube dispersion, mixing the carbon nanotube dispersion and a monomer solution, and polymerizing the monomer. However, the carbon nanotubes have poor dispersion in the organic solvent, which affects the uniformity of the carbon nanotubes in the composite structure. Another method include completely melting the polymer, and mixing the melted polymer and the carbon nanotubes. However, the carbon nanotubes have poor dispersion in the melted polymer because the melted polymer has greater viscosity. Thus, the uniformity of the carbon nanotubes in the composite structure is still poor. When the carbon nanotube composite structure is used as the electron transport layer of the OLED, the electron transport layer has poor ability to transmit electrons.
What is needed, therefore, is to provide an organic light emitting diode and a method for making the same that can overcome the above-described shortcomings.